Background: Unprotected left main coronary artery disease was defined as having a left main coronary artery stenosis of greater than 50% and the absence of bypass grafts to the left anterior descending or left circumflex coronary arteries. Objective: The purpose of this study was to assess major adverse cardiovascular events (MACE) and its relationship to syntactic score in connection to short and intermediate term clinical outcomes of Percutaneous Coronary Intervention (PCI) in unprotected left main coronary artery (LMCA) illness. Patients and methods: A total of 50 patients with unprotected left main coronary artery (ULMCA) disease were enrolled in a prospective study and received drug-eluting stent (DES) implantation at Cardiology Department, Mansoura University Hospital, and National Heart Institute, Egypt from June 2018 to December 2019. Result: ROC curve analysis showed that Syntax score was the best method as a marker for prediction of MACE; it had sensitivity of 73.3%, specificity of 77.1% at AUC of 0.770 with cut off value >32.5. On univariate analysis, age, ST-elevation myocardial infarction (STEMI), osteal, mild, distal, as well as all LM length disease were risk factors of MACE (P <0.05). However, on multivariate analysis, osteal, all LM disease, STEMI, and high SYNTAX score were significant predictors of MACE (P <0.05). Conclusion: ULMCA stenosis can be successfully treated by stenting. Stenting of distal LM lesions with low or intermediate SYNTAX scores by site evaluation, PCI with drug-eluting stents, and short- and intermediate-term follow-up, results in a lower incidence of mortality, stroke, or myocardial infarction.